题意:有N朵花,在M种颜色中选择恰好k种不同的颜色,将这N朵花染色,要求相邻的两朵花颜色不相同. 分析:若限制改为选择不超过k种颜色将N朵花朵染色,则方案数\(f(N,k) = k*(k-1)^{N-1}\),第一朵可以在k个颜色中任意选择,第二朵可以有k-1个选择,第三朵也有k-1.... 但是f(N,k)种方案中包含了使用了少于k个颜色的方案数,要减去这些方案数.设没有使用的颜色数为i,当i=1时,减去只使用1种颜色的方案数\(C(k,1)*f(N,k-1)\);当i=2时,方案数已经被i=…

Problem Description Elves are very peculiar creatures. As we all know, they can live for a very long time and their magical prowess are not something to be taken lightly. Also, they live on trees. However, there is something about them you may not kn…

http://acm.hdu.edu.cn/showproblem.php?pid=5441 Travel Time Limit: 1500/1000 MS (Java/Others)    Memory Limit: 131072/131072 K (Java/Others)Total Submission(s): 2061    Accepted Submission(s): 711 Problem Description Jack likes to travel around the wo…

http://acm.hdu.edu.cn/showproblem.php?pid=5444 Elven Postman Time Limit: 1500/1000 MS (Java/Others)    Memory Limit: 131072/131072 K (Java/Others)Total Submission(s): 939    Accepted Submission(s): 520 Problem Description Elves are very peculiar crea…

Elven Postman Time Limit: 1500/1000 MS (Java/Others)    Memory Limit: 131072/131072 K (Java/Others)Total Submission(s): 591    Accepted Submission(s): 329 Problem Description Elves are very peculiar creatures. As we all know, they can live for a very…

ACM ICPC Central Europe Regional Contest 2013 Jagiellonian University Kraków Problem A: Rubik’s RectangleProblem B: What does the fox say?Problem C: Magical GCDProblem D: SubwayProblem E: EscapeProblem F: DraughtsProblem G: History courseProblem H: C…

2019-2020 ICPC, Asia Jakarta Regional Contest (Online Mirror, ICPC Rules, Teams Preferred) easy: ACEGHK medium-easy: BJL medium: D ?????: I A. B. C. 对 \(R[],C[]\) 分别按奇偶性分段. 网! D. 考虑 check 一个串,枚举右走对应的前缀 pre,下走对应的后缀 suf. 把每行反串拼接中间连特殊字符,建 SA,能 match 上 p…

摘要 本文主要给出了2014-2015 ACM-ICPC, Asia Xian Regional Contest的部分题解,说明了每题的题意.解题思路和代码实现,意即熟悉区域赛比赛题型. Built with Qinghuai and Ari Factor 题意 判断是否是Q数列,只要数列中每个数均能够被3整除就是Q数列. 解题思路 需要特判一下0的情况. 代码 #include <cstdio> int main() { int T; int n; ; scanf("%d"…

The Problem to Slow Down You Time Limit: 1 Sec Memory Limit: 256 MB 题目连接 http://acm.hust.edu.cn/vjudge/contest/view.action?cid=93645#problem/G Description http://7xjob4.com1.z0.glb.clouddn.com/76e435d3c21fa3cbeef1e76780086dc4 Input   Output Sample In…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=5458 Problem Description Given an undirected connected graph G with n nodes and m edges, with possibly repeated edges and/or loops. The stability of connectedness between node u and node v is defined by…